1. Field of the Invention
The present invention relates to a braking apparatus for a vehicle, and more specifically, a vehicle having an air-cooled brake disk and a protective cover having an air flow opening feeding cooling air to the brake disk.
2. Description of Related Art
Vehicles such as passenger motor vehicles or trucks use disk brakes. Disk brakes generate thermal energy during braking dissipated by ventilating the brake disks. Typically, a brake disk includes radial flow ducts in the brake disk. Centrifugal force occurring because of rotational movement of the brake disk initiates air flow through the radial flow ducts, the air flows through openings in the brake disk. The openings situated in the vicinity of a wheel hub, to which the brake disk is attached. Brake disks of this type are also called internally ventilated brake disks.
Brake disks are components of a vehicle subjected directly to the environment, including weather conditions. In general, the brake disks are adjacent the vehicle wheels, in particular in the wheel rims thereof. To protect the brake disks, which rotate with the wheels, against contamination that may impair braking action, in particular against spray water, a disk-shaped protective cover covers at least the side of the brake disk on the vehicle inside over as much of the surface area as possible.
The protective cover on the side of the brake disk protecting against contamination and spray water may impair the ventilation of the brake disk. To provide cooling of the brake disk, the protective cover includes an air flow opening feeding in cooling air to the brake disk.
Cooling air is continually fed into the brake disk, in particular even when cooling of the brake disk is unnecessary because of low loading. Also, the air flow opening in the protective cover may reduce the actual function of the protective cover, namely to protect the brake disk against spray water and contamination.